in tcl_core.c [283:288]
void set_vari(Tcl_Interp* interp, char *var1, char *var2, int var)
{
if (Tcl_SetVar2Ex(interp, var1, var2, Tcl_NewIntObj(var), TCL_LEAVE_ERR_MSG) == NULL) {
ap_log_error(APLOG_MARK, APLOG_NOERRNO|APLOG_ERR, 0, NULL, "Tcl_SetVarEx2(%s, %s, %d): %s", var1, var2 ? var2 : "NULL", var, Tcl_GetStringResult(interp));
}
}